In [1]}, the authors studied a pair of SUs as the secondary transmitter (ST) and secondary receiver (SR), working in a hybrid method that incorporates HTT and AB algorithms to improve the performance of the system. However, this work considers only a pair of users, not a multi-hop, as studied in this paper. In [2]}, a CWPCN took into consideration that enjoys a hybrid scheme working with either HTT or AB algorithms. However, the scenario investigated in [2]} is not a multi-hop one, so it cannot compare with our work. The scenarios investigated in [4]}, [5]}, [6]}, [7]}, are also a WPCN, therefore as [2]}, these papers cannot compare with a multi-hop scenario investigated in this paper. Besides, the works in [4]}, [6]}, [7]} have not been studied in the context of cognitive radio.
